﻿<p>The <em>IfcSurfaceOfLinearExtrusion</em> is a surface derived by sweeping a curve along a vector.</p>

<blockquote class="extDef">
NOTE&nbsp; Definition according to ISO/CD 10303-42:1992<br>
This surface is a simple swept surface or a generalized cylinder obtained by sweeping a curve in a given direction. The parameterization is as follows where the curve has a parameterization &lambda;(<em>u</em>):</p> 

<blockquote>
  <p style="font-size:inherit">V = ExtrusionAxis</p> 
  <img src="../../../figures/ifcsurfaceoflinearextrusion-math1.gif" width="124" height="22">
</blockquote>

The parameterization range for <em>v</em> is -&infin; &lt; <em>v</em> &lt; &infin; and for <em>u</em> it is defined by the curve parameterization.</blockquote> 

<blockquote class="note">NOTE&nbsp; Entity adapted from <strong>surface_of_linear_extrusion</strong> defined in ISO
10303-42.</blockquote>

<blockquote class="history"> 
HISTORY&nbsp; New entity in IFC2x.
</blockquote> 

<p class="spec-head">Informal Propositions:</p> 
<ol> 
<li>The surface shall not self-intersect</li> 
</ol>